| Dougoufana Samake 1,2* | Bintou Ly 1*| Alpha Seydou Yaro 1,2 | Josue Poudiougo 1,2 | Alassane dit Assitoun 1,2 | and | Bernard Sodio 2 |
Affiliation.
1. University of Fianarantsoa | Ecole Doctorale Géochimie et Chimie Médicinale (GEOCHIMED) | Fianarantsoa 301 | Madagascar | 2. University of Antananarivo | Mention Génie Rural | Ecole Supérieure Polytechnique | Madagascar | 3. University of Picardie |Laboratoire de Glycochimie, des Antimicrobiens et des Agroressources FRE CNRS3517 | Amiens | France | 4. University of Antananarivo |Laboratoire de Chimie des Substances Naturelles et Chimie Organique Biologique (LCSN/COB) | Antananarivo | HYPERLINK "mailto:Madagascar| learasoa3@yahoo.fr|" Madagascar |
This article is made freely available as part of this journal's Open Access:ID|Rivoandry-Ref04-ajiras021221 |
ABSTRACT Background: Bremeria arachnocarpa Wernham is a small tree endemic of Madagascar. The decoction of its leaves is used in traditional medicine for the treatment of yellow fever, in case of poisoning. Aim of the study: This work aims to evaluate the chemical constituents, antioxidant and antimicrobial activity of this plant. Materials and methods: The chemical constituents of the hexane-soluble and ethyl acetate-soluble parts of the crude ethanolic extract of the leaves were studied. Column chromatography and TLC methods allow the isolation of products. The structures of the isolated products were identified by concerted analysis of the 1D and 2D NMR spectra and by comparison with the literatures. The crude ethanolic extract and hexane-soluble, ethyl acetate-soluble and butanol-soluble parts of the crude ethanolic extract were used for biological activity. The antimicrobial activity was test by diffusimetric method and the antioxidant activity of the extracts was evaluated using DPPH° free radical scavenging. Results: According to this method, crude ethanolic extract of Bremeria arachnocarpa leaves exhibited a high antioxidant capacity (IC50= 10.3 µg / ml), the antioxidant capacity being more powerful than of α-tocopherol (10.67 µg / ml), used as standard drug. Its antioxidant capacity is focalised in butanol-soluble part of the crude ethanolic extract (IC50= 12.34 μg/ml). The results of antimicrobial activity showed the ineffectiveness of the extracts against most of the strains tested. The fractionation of the hexane-soluble and ethyl acetate-soluble parts of the crude ethanolic extract led to the isolation of three known compounds trioleine 1, acylated β-sitosterol 2 and ursolic acid 3. Keywords: Trioleine, ursolic acid, acylated β-sitosterol, Antioxidant, Antimicrobial, Bremeria arachnocarpa, NMR.
